Bis-Diethylamino Silane (BDEAS) 전구체를 사용하여 원거리 플라즈마 원자층 증착법으로 증착한 SiO2 박막 특성 평가

Abstract

For various electrical device applications, the low temperature SiO2 film growth has been studied using atomic layer deposition. In this study, we characterized bis-diethylamino silane (H2Si((N(C2H5)2)2, BDEAS) precursor for low temperature SiO2 growth using by remote plasma atomic layer deposition (RPALD) by focusing the control of typical impurities in ALD grown SiO2 such as hydrogen and nitrogen, leading to the degradation in SiO2 electrical properties. XPS analysis indicated that the hydrogen and nitrogen incorporation into the film causes a Si 2p binding energy shift in SiO2 films with deposition temperature, revealing the reduced impurity concentration as the deposition temperature increases. Consistently, the analysis on O 1s and N 1s XPS peaks also confirms the impurity reduction with the deposition temperature. AES analysis results proved the stoichiometric SiO2 deposition by RPALD with other impurities at the concentration level < 1%. The electrical properties attained from C-V and I-V analysis indicate that hydrogen impurity causes the degradation of SiO2 electrical properties as forming Si-OH and Si-H bonds due to the incomplete thermal decomposition of ligands in BDEAS but these impurities can be controlled by increasing deposition temperature as also confirmed in SIMS analysis. BDEAS precursor was suitable for RPALD of SiO2 at the low temperature, except for hydrogen impurities that cause degradation of electrical properties in some degree.